Compaq TFT450 No Power
I have a compaq TFT450 lcd monitor which won't power up. The input
fuses on the 5v and 12v inputs are fine. After the each fuse there is a 470 micro farad capacitor. I have a multi-meter but I am not too sure on how to test the capacitors ? To test the capacitors you will need an ESR meter. It is very well possible that one or more electrolytic capacitors are bad. Coincedently I repaired a Compaq TFT screen yesterday (randomly flashing lines); while tracking down the cause of the problem I did notice that many of the SMD caps did have a poor ESR. In this case the problem was caused by a bad electrolytic cap near the power input. -- Peter van Merkerk peter.van.merkerk(at)dse.nl |
Compaq TFT450 No Power
Peter van Merkerk wrote:
I have a compaq TFT450 lcd monitor which won't power up. The input fuses on the 5v and 12v inputs are fine. After the each fuse there is a 470 micro farad capacitor. I have a multi-meter but I am not too sure on how to test the capacitors ? To test the capacitors you will need an ESR meter. An alternative for using an ESR meter is to use a oscilloscope to watch the signal over the capacitor when the device is powered on. If the capacitor is good you should see no or only a very small signal. -- Peter van Merkerk peter.van.merkerk(at)dse.nl |
Compaq TFT450 No Power
Hi Peter,
I think that its the two surface mount capacitors near the fuse terminals. Is it simply the case of removing them by de-soldering the two contact points on either side of the caps ? Regards Dave K. "Peter van Merkerk" wrote in message ... Peter van Merkerk wrote: I have a compaq TFT450 lcd monitor which won't power up. The input fuses on the 5v and 12v inputs are fine. After the each fuse there is a 470 micro farad capacitor. I have a multi-meter but I am not too sure on how to test the capacitors ? To test the capacitors you will need an ESR meter. An alternative for using an ESR meter is to use a oscilloscope to watch the signal over the capacitor when the device is powered on. If the capacitor is good you should see no or only a very small signal. -- Peter van Merkerk peter.van.merkerk(at)dse.nl |
All times are GMT +1. The time now is 10:14 AM. |
Powered by vBulletin® Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Copyright ©2004 - 2014 DIYbanter